"Torn," filmed in the East Bay, centers on two grieving mothers roiling from the aftermath of a shopping mall explosion that killed their teenage sons. Director Jeremiah Birnbaumsays, "The actors had to live that pain of losing a child for the whole month that we shot the film. It was great experience for our leads, but they were exhausted by the end of the shoot."

Birnbaum, who runs the San Francisco School of Digital Filmmaking, flew to Karachi to cast actress Mahnoor Baloch as the Pakistani American real estate agent who gets interrogated by police because of her late son's activities. He says, "I wanted to make 'Torn' because I felt there's so many negative stories (about the Muslim American community). It seems like a lot of news outlets pump fear out there, so with this film I wanted to put a positive message into the world."

Facebook Chief Privacy Officer Michael Richter wrote the "Torn" screenplay. He says, "The mothers in the film are driven to prove that their sons didn't do it, but as they investigate the incident they realize there are things they didn't know about their own sons. One of the themes that drew me to write the film was the question of 'How well do you really know the people around you?' "

Time is coming for ode to Tesla's achievement

Slowly but surely, Joseph Sikorskiis getting closer to his dream. He wants to make a feature film about Nikola Tesla, the Serbian American inventor of alternating current electricity technologies. Portrayed by David Bowieseven years ago in "The Prestige," Tesla died penniless in 1943 after being outmaneuvered on the business front by Thomas Edison.

Sikorski donated $33,000 from his own film budget toward the purchase of the Wardenclyffe site in Long Island where the scientist did much of his research. Last month he screened a promotional teaser of his movie-in-progress, "Fragments From Olympus: The Vision of Nikola Tesla" for the United Nations Serbian Mission.

Still room in movie biz to do things 'old school'

The revolution in computer-generated effects looms over the traditional bricks-and-mortar craftsmanship that traditionally powered onscreen action. But prop master Russell Bobbitt, who's overseen the manufacture of Iron Man's arc reactor artificial heart and scores of other devices, says he's not worried about being replaced by a computer.

"Some people in my field get worried or afraid or upset when the filmmakers say, 'We'll do it in post,' " he says. "It hurts their feelings. But the way I look at it, there's still this old-school nostalgia way of thinking amongst our production designers, costume designers, directors. They want something tangible. For that reason, we're still working in the business."

Producing the perfect "tangible" prop can be an arduous process. Bobbitt and his team designed more than 200 variations of Thor's iconic hammer before arriving at the weapon used by actor Chris Hemsworthin the 2011 superhero movie. The hammer will also be featured in Marvel Entertainment's sequel "Thor 2: The Dark World," opening next month.

Bobbitt, who also managed the prop work on "Oz the Great and Powerful," says he savors the variety of experiences afforded by his job. "One day I'll be standing on the Yellow Brick Road and the next day I'm in an elevator with a 60-year-old naked women making "The Hangover" with Bradley Cooper, Ed Helmsand Zach Galifianakisin Las Vegas." Bobbitt says, "Every morning when I get in my car, I laugh out loud." {sbox}